ios - 在Objective-C的UIAlertController下添加Textview

如何在 UIAlertController 下添加文本 View ？我已经尝试了下面的方法，但 textview 没有正确显示。

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Comments" message:@"Enter your submit comments" preferredStyle:UIAlertControllerStyleAlert];
alertController.view.autoresizesSubviews = YES;

UITextView * alertTextView = [[UITextView alloc] initWithFrame:CGRectZero];
alertTextView.translatesAutoresizingMaskIntoConstraints = NO;
alertTextView.backgroundColor = [UIColor greenColor];

NSLayoutConstraint *leadConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:alertTextView attribute:NSLayoutAttributeLeading multiplier:1.0 constant:-8.0];
NSLayoutConstraint *trailConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:alertTextView attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:8.0];

NSLayoutConstraint *topConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:alertTextView attribute:NSLayoutAttributeTop multiplier:1.0 constant:-64.0];
NSLayoutConstraint *bottomConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:alertTextView attribute:NSLayoutAttributeBottom multiplier:1.0 constant:64.0];
[alertController.view addSubview:alertTextView];
[NSLayoutConstraint activateConstraints:@[leadConstraint, trailConstraint, topConstraint, bottomConstraint]];

UIAlertAction *okButtonAction = [UIAlertAction actionWithTitle:@"Ok" style:UIAlertActionStyleDefault handler:^(UIAlertAction *  action) {
    [alertTextView resignFirstResponder];

}];
UIAlertAction *cancelButtonAction = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {

}];
[alertController addAction:okButtonAction];
[alertController addAction:cancelButtonAction];

[self presentViewController:alertController animated:YES completion:nil];

最佳答案

看看这个代码。已测试

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Some title"
                                                                         message:@"\n\n\n\n\n\n\n\n"
                                                                  preferredStyle:UIAlertControllerStyleAlert];

UIAlertAction* okay = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault
                                           handler:^(UIAlertAction * action) {
                                               //Do Some action here
                                           }];
UIAlertAction* cancel1 = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleDefault
                                               handler:^(UIAlertAction * action) {
                                                   [alertController dismissViewControllerAnimated:YES completion:nil];
                                               }];
[alertController addAction:okay];
[alertController addAction:cancel1];

alertController.view.autoresizesSubviews = YES;
UITextView *textView = [[UITextView alloc] initWithFrame:CGRectZero];
textView.translatesAutoresizingMaskIntoConstraints = NO;
textView.editable = YES;
textView.dataDetectorTypes = UIDataDetectorTypeAll;
textView.text = @"Some really long text here";
textView.userInteractionEnabled = YES;
textView.backgroundColor = [UIColor whiteColor];
textView.scrollEnabled = YES;
NSLayoutConstraint *leadConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeLeading relatedBy:NSLayoutRelationEqual toItem:textView attribute:NSLayoutAttributeLeading multiplier:1.0 constant:-8.0];
NSLayoutConstraint *trailConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeTrailing relatedBy:NSLayoutRelationEqual toItem:textView attribute:NSLayoutAttributeTrailing multiplier:1.0 constant:8.0];

NSLayoutConstraint *topConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:textView attribute:NSLayoutAttributeTop multiplier:1.0 constant:-64.0];
NSLayoutConstraint *bottomConstraint = [NSLayoutConstraint constraintWithItem:alertController.view attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:textView attribute:NSLayoutAttributeBottom multiplier:1.0 constant:64.0];
[alertController.view addSubview:textView];
[NSLayoutConstraint activateConstraints:@[leadConstraint, trailConstraint, topConstraint, bottomConstraint]];

[self presentViewController:alertController animated:YES completion:^{

}];

关于ios - 在Objective-C的UIAlertController下添加Textview，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47789708/